DOCUMENT TITLE: PROCESS AND UTILITY DESCRIPTION - CENTRAL DEGASSING STATION PROJ ECT No. :P 14364 ADCO DOC. NO.: 58.01.91.1601

REV 1DATE: 28-Sep-11 CONTRACTOR DOC. No. A049-001-02-41-PD-1001PAGE:2OF20 TABLE OF CONTENTS ABBREVIATIONS......................................................................................................................................................31.0 PROJECTINTRODUCTION............................................................................................................................42.0 PROJECTSCOPE..........................................................................................................................................53.0 PURPOSEOFDOCUMENT...........................................................................................................................64.0 CENTRALDEGASSINGSTATION...................................................................................................................64.1 WELLHEAD.............................................................................................................................................................64.2 INLETFACILITIES........................................................................................................................................................6a) MultiSelectorManifolds......................................................................................................................................6b) ProductionHeaders,TestHeadersandMPFMs...................................................................................................7c) PigReceiversandProductionManifolds..............................................................................................................74.3 PRODUCTIONSEPARATORS..........................................................................................................................................74.4 CRUDEOILEXPORTSYSTEM........................................................................................................................................84.5 PRODUCEDWATERHANDLING....................................................................................................................................94.6 GASCOMPRESSIONANDDISTRIBUTION.......................................................................................................................104.6.1 GasCompressor:.................................................................................................................................................104.6.2 InjectionGasdistribution...................................................................................................................................124.7 GASDEHYDRATION..................................................................................................................................................124.8 CHEMICALINJECTIONSYSTEMS..................................................................................................................................134.9 VAPORRECOVERY...................................................................................................................................................134.10 FUELGAS..............................................................................................................................................................144.11 FLARESYSTEMS.......................................................................................................................................................144.11.1 HP,HPColdandHPSpareSystems....................................................................................................................144.11.2 TankFlareSystem...............................................................................................................................................154.11.3 FlareDrainSystem..............................................................................................................................................164.12 PROCESSANDCLOSEDDRAINS...................................................................................................................................164.12.1 ClosedDrainSystem...........................................................................................................................................164.12.2 ProcessDrainSystem..........................................................................................................................................174.12.3 TundishSystem...................................................................................................................................................174.13 COMPRESSEDAIRSYSTEM........................................................................................................................................174.14 NITROGENGENERATIONSYSTEM................................................................................................................................184.15 DIESELFUEL...........................................................................................................................................................184.16 EMERGENCYDIESELGENERATOR................................................................................................................................184.17 POTABLEWATERSYSTEM.........................................................................................................................................184.17.1 PotableWaterGenerationSystem.....................................................................................................................184.17.2 PotableWaterStorageandDistribution............................................................................................................195.0 REFERENCES.............................................................................................................................................206.0 ANNEXURES.............................................................................................................................................20 DOCUMENT TITLE: PROCESS AND UTILITY DESCRIPTION - CENTRAL DEGASSING STATION PROJ ECT No. :P 14364 ADCO DOC. NO.: 58.01.91.1601

REV 1DATE: 28-Sep-11 CONTRACTOR DOC. No. A049-001-02-41-PD-1001PAGE:3OF20 ABBREVIATIONS ADCO Abu Dhabi Company for Onshore Oil Operations BOPDBarrels of Oil per Day BPDBarrels Per Day BWPD Barrels of Water per Day CDSCentral Degassing Station FEEDFront End Engineering Design GASCOAbu Dhabi Gas Industries HPHigh Pressure IAInstrument Air KOKnock Out LAHLevel Alarm High LALLevel Alarm Low LPLow Pressure MThousands MOLMain Oil Line MPFM Multiphase Flow Meter MSMMultiselector Manifold RDSRemote Degassing Station SCFDStandard Cubic Feet per DayTh-A/B Thamama-A and Thamama-B (producing zones) Th-FThamama-F (producing zone) VRCVapor Recovery Compressor DOCUMENT TITLE: PROCESS AND UTILITY DESCRIPTION - CENTRAL DEGASSING STATION PROJ ECT No. :P 14364 ADCO DOC. NO.: 58.01.91.1601

REV 1DATE: 28-Sep-11 CONTRACTOR DOC. No. A049-001-02-41-PD-1001PAGE:4OF20 1.0PROJECT INTRODUCTION ADCO has been chartered by their shareholders to expand sustainable crude oil production fromitscurrentlevelof1.4millionbarrelsoilperday(MMBOPD)to1.8MMBOPD. Accordingly, ADCO has undertaken projects for development of its marginal fields to help achieve this target, which involves increasing production at existing Bab & North-East Bab oilfieldsandbeginningproductionsfromtwonewoilfields,namely,BidaAlQemzan& Qusahwira. Qusahwira is a new undeveloped field located about 80 Km Southeast of existing Asab oil fieldandapproximately200kmsouth-southeastofAbuDhabicity.Thelocationofthe Qusahwira field is depicted in Figure 1-1 below: Figure 1-1 The development drilling commenced at the end of year 2006 & full field development shall becompletedintwophases.ThedevelopmentunderPhase-1islimitedtothesouthern block of the field, which involves developing Thamama Zones A/B and F. The first phase of Qusahwira project will contribute 30 MBOPD to 1.8 MMBOPD scheme from year 2013 for a periodofaboutfiveyears.Aftercompletionofsecondphase,itstotalproductionshall increaseto42.47MBOPD.Additionally,20MBOPDfromMenderandSouthEastfields shall be implemented in future. DOCUMENT TITLE: PROCESS AND UTILITY DESCRIPTION - CENTRAL DEGASSING STATION PROJ ECT No. :P 14364 ADCO DOC. NO.: 58.01.91.1601

REV 1DATE: 28-Sep-11 CONTRACTOR DOC. No. A049-001-02-41-PD-1001PAGE:5OF20 2.0PROJECT SCOPE ThePhase-1ofQusahwiraFullFieldDevelopmentProjectshallhavefacilitiesatthree locations and an interface with the existing Asab oil field. Broadly, the following facilities are part of Phase-1 project: -Constructing a new Central Degassing Station (CDS) at Qusahwira. It shall include facilities as below: oInletmanifoldsforreceivingproductiontransferlinefromanewRemote Degassing Station (RDS-1) & two direct production flow lines oMulti phase flow meters (MPFMs) oTwo trains of three phase production separators oTwo trains of four stage gas compression oGas injection directly to four gas injectionwells oTwo glycol contactors & one common glycol regeneration oVapor recovery compressor package oProduced water treatment & disposal to five disposal wells oMain oil Line (MOL) booster pumps and MOL pumps for exporting crude oil to Asab CDS oVarious supporting utilities & chemical injections systems. -ConstructinganewRemoteDegassingStation(RDS-1)atapproximately9.2km southwestofthenewQusahwiraCDS.TheRDS-1shallgather&test22 production flow lines and deliver the raw crude to the Qusahwira CDS.This shall also serve as distribution points for injection gas from the Qusahwira CDS to 5 gas injectionwellsinThamamaA/Bzoneforpressuremaintenancebesidesvarious supporting utilities and chemical injection facilities. -Constructing two new Water Injection Clusters (WIC-1 and WIC2) southwest of the QusahwiraCDSforwaterinjectiontooilwellsinThamamaFzoneforpressure maintenance including chemical injection facilities. Four wells shall be served from WIC-1 and one well from WIC-2. -Constructing a 20 production fluid transfer line from RDS-1 to the CDS-Constructing a 6 gas injection trunk line from the CDS to RDS-1for distribution to gas injection wells. -Constructing 22 flow lines from producing wells to RDS-1 and 2 flow lines directly to the CDS and constructing 5 gas injection flow lines from RDS-1 and 4 gas injection lines directly from the CDS. -Constructing a 14 Main Oil Line (MOL) to the CDS at Asab oil field. DOCUMENT TITLE: PROCESS AND UTILITY DESCRIPTION - CENTRAL DEGASSING STATION PROJ ECT No. :P 14364 ADCO DOC. NO.: 58.01.91.1601

REV 1DATE: 28-Sep-11 CONTRACTOR DOC. No. A049-001-02-41-PD-1001PAGE:6OF20 -Providing expandability for future facilities at CDS to support 62.47 MBOPD crude oil production at Qusahwira by: Providing plot space for a third train of production separator, a third train of gas compression, gas dehydration & glycol regeneration, additional water separation tanks and additional produced water disposal pumps. Providing utility systems for both phase-1 and phase-2 3.0PURPOSE OF DOCUMENT This document describes the process at the new Central Degassing Station (CDS) that will collect production fluids, separate the oil, gas and water phases, and treat each phase as described below. 4.0CENTRAL DEGASSING STATION 4.1Well Head TheproductionfluidsflowfromthewellthroughthehydraulicallyactuatedSubsurface SafetyValve(SSSV-XXXX-02)andSurfaceSafetyValve(SSV-XXXX-03)tothesurface flow line gathering system and to the RDS.The SSSV is held open by hydraulic oil system pressure.In the event of a well head fire, a HP fusible plug on the hydraulic line opens, releasing hydraulic pressure, closing the valve and shutting in the well.The SSV is held openbyhydraulicoilpressureandcloseswithlossofhydraulicsystempressureon opening of one of four LP fusible plugs in event of fire, located near the well head. Also SSVclosesbasedonHighPressurePilotvalve(HPPV)andLowPressurePilotvalve (LPPV) set pressure. HandswitchesonthelocalWellHeadControlPanelopen/closetheSSSVandSSV.Hydraulicfluidisaself-containedsystem,pumpedbyahydraulicfluidpumpinthewell head control panel.The pump and the panel are solar powered.The well head can be manually shut-in with Master Valve and the Wing Valve. 4.2Inlet Facilities The Central Degassing Station (CDS) Separators receive produced fluids from RDS-1 and directly from two wells in the vicinity of the CDS. During phase 2 it will receive produced fluid from RDS-2 also. Well fluid from the two wells to CDS receive through two 6 flow lines. Each Flow line from well has a manual block valve at the CDS fence line Wells flowing directly to the CDS are combinedthroughMulti-SelectorManifoldsanddirectedtotheProductionandTest headers.All produced fluids enter the CDS Separators through the Production Manifold. a)Multi-Selector Manifolds TwoMulti-SelectorManifolds(MSMs)(58-01-M-0201/M-0202)willbeinstalledtoaccept Phase-1productionwellsattheCDS.MSMsmaybeconnectedtoacombinationof Thamama-A/B or Thamama-F wells (Only Two Thamama-A/B wells Qw 020 and Qw 021 are directly connected to CDS in Phase-I). Qw 020 is connected to MSM, 58-01-M-0201 and Qw 021 is connected to 58-01-M-0202. Space is provided for third MSM, which shall be added in Phase-2. The MSM provides the ability to gather and combine the flow of produced fluids from up to seven (7) wells.Well flow lines are routed to the MSM assembly, where the well fluids are combinedwithinthebodyoftheMSM.Thecombinedfluidsflowouttotheproduction DOCUMENT TITLE: PROCESS AND UTILITY DESCRIPTION - CENTRAL DEGASSING STATION PROJ ECT No. :P 14364 ADCO DOC. NO.: 58.01.91.1601

REV 1DATE: 28-Sep-11 CONTRACTOR DOC. No. A049-001-02-41-PD-1001PAGE:7OF20 header.IndividualproductionheadersfromtheMSMsareroutedtotheProduction Manifold (M-0210). A rotating plug located within the body of the MSM can align with any of the seven inlet connections and divert the flow from an individual well to the test header through the test outlet. The test header flows through a multi-phase flow meter where flow measurements are taken and recorded before combining with other wells in the production header.Welltestingisanautomatedprocedurewiththeprovisionforlocalorremote operation. In the event that test meter is offline, the rotating plug is aligned with the blinded connection, so no fluid flows to the test outlet. The purpose of well testing is to obtain actual well performance data, including individual oil, water and gas rates, and to accumulate a database of well performance history.This data is used to evaluate reservoir performance against models allowing diagnosis of well performance issues and recommendation of remedial procedures. b)Production Headers, Test Headers and MPFMs During normal operation, fluids flow directly from each MSM to a 10 Production Header.TheProductionHeadersareprotectedagainstoverpressurebyHighIntegrityPressure Protection System (HIPPS), which consists of two shutdown valves, logic solver and three pressure transmitters (2 out of 3) installed at the Production Header. This is the sole means of overpressure protection. Operation of the HIPPS is controlled through the HIPPS Logic SolverwithstatusindicatedattheDCS.ApressuretransmitterupstreamoftheHIPPS valves works in combination with the downstream pressure transmitters to determine the differentialpressureacrosstheHIPPSvalves.Thisdifferentialpressure(DPI)across HIPPS valves is used as a permissive to start logic against high differential pressure across the HIPPS valves.Produced fluid flowing from the MSMs test connection is periodically diverted, one well at a time, to one of two 4Test Headers.Each Test Header includes a Multi-Phase Flow Meter (MPFM 58-01-FT-0201/FT-0202) that separately measures flow of the oil, gas and water phasesandanauto-samplerforfluidanalysis.Thepurposeofwelltestingistoobtain actualwellperformancedata,includingindividualoil,waterandgasrates,andto accumulate a database of well performance history. c)Pig Receivers and Production Manifolds Production fluids flow from RDS 1 through 20 transfer line to the CDS. A pig Receiver (58-01-RP-1301) is installed at the end of 20 transfer line at CDS inlet in order to receive the piglaunchedfromRDS-1duringthepiggingoperation.TheCDSInletManifoldreceives producedfluidsfromtheRDS-120transferlineandtheProductionHeadersfromCDS MSMs (M-0201/M-0202). There are two 24 production manifolds routed to two Production Separatorsinphase-1.ThirdproductionmanifoldshallbeaddedinPhase-2.Provisions allowforfutureproductiontie-ins.Throughaseriesofcross-overheadersandmotor operated valves in-coming produced fluids are routed through the Production Manifold to ProductionSeparators(58-01-V-0301/V-0302)inPhases1.Producedfluidfromlow pressurecompressorsuctiondrums(58-01-V-3112-01/V-3122-01)andhighpressure compressor suction drums (58-01-V-3113, V-3123) in Compression Trains 1 and 2 (Phase-1),ClosedDrainDrum(58-01-V-6701),ProcessDrainDrum(58-01-V-6702),Recovered OilCollectionTank(58-01-V-1510)andFlareKODrums(58-39-V-1911/V-1931/V-1941) are returned to the Separation Train production headers. 4.3Production Separators Fromtheinletfacilities, productionfluidsflowtothetwoProductionSeparators58-01-V-0301/V-0302thatseparategasandwaterfromtheoil.Spaceisprovidedforthird DOCUMENT TITLE: PROCESS AND UTILITY DESCRIPTION - CENTRAL DEGASSING STATION PROJ ECT No. :P 14364 ADCO DOC. NO.: 58.01.91.1601

REV 1DATE: 28-Sep-11 CONTRACTOR DOC. No. A049-001-02-41-PD-1001PAGE:8OF20 ProductionSeparatorwhichshallbeaddedinPhase-2.Onestageofseparationis provided at Qusahwira and the oil is pumped to ASAB for further treatment.Each of the ProductionSeparatorsissizedtoprocess30MBOPDofstocktankoil.Normallytwo separatorsareworkinginparallel.However,incaseoneoftheseparatorsisunder maintenance, the other separator will be in operation at sustainable flow.The separator operating pressure is 3.5 barg.The operating temperature is 60 deg C in summer and 15 deg C in winter. The separator pressure is maintained at 3.5 barg through a back pressure controlvalveprovidedontheproducedgaslinegoingtogascompressor.Thereis provisionofroutingoftheproducedgastoflareincaseofhigherpressureofthe Production Separator. The level control valves provided on produced water line in outlet of each Separator, controls the interface level of the Separators. The oil flows over a weir into thefarendofthevessel.LevelcontrolisprovidedfortheOil.RefertoReference2, Equipment Sizing Philosophy. 4.4Crude Oil Export System The crude oil export system consist of MOL booster pumps and MOL pumpsMOL Booster Pumps Thecrudeoilexportpumpsconsistoftwoboosterpumps(oneoperatingwithaspare) dedicated to each production separator i.e. total four booster pumps (58-01-P-0901/P-0902 & 58-01-P-0903/P-0904) which feed to MOL pumps(58-01-P-1001/P-1002). Two additional Mol booster pumps shall be added in phase-2 corresponding to third production separator. The rated capacity is 230.2 m3/hr (at operating condition) per pump. The MOL booster pump takes suction from the respective production separator. A strainer is provided in suction of each MOL booster pump. The MOL booster pumps discharge to a common line going to MOL pumps suction. The flow control is provided for MOL Booster pump discharge which is reset by oil level control of the Separator from which MOL booster pump is taking suction.Forminimumcirculationflowanautorecyclevalveisprovidedondischargeofeach booster pump, which recycles the oil back to production separator from which the booster pump is taking suction. TheMOLBoosterpumpsareprovidedwithMOVsondischargeline.TheMOVshallbe linked to the start/stop logic of the MOL Booster pump. When the pump starts, the MOV shall open. When the pump stops, the MOV shall close MOL Pumps InPhase-1thereisoneoperatingandonespareMOLpumps(58-01-P-1001/P-1002). Space is provided for a third pump which shall be added in Phase-2, so that two pumps will beoperatingandonewillbespare.Theratedcapacityis276.3m3/hr(atoperating condition) per MOL pump. The MOL pumps shall have four stages in phase-1 and 9 stage in Phase-2. Crude oil from the MOL Booster Pumps is pumped by the MOL Pumps through the MOL to the ASAB. One operating and one standby MOL basket strainers (58-01-ST-1001/ST-1002)areprovidedincommonpumpdischargeline.MOLpumpssuction pressure(i.epressureofcommonsuctionlineoftheMOLpumps)iscontrolledbythe pressurecontrolvalvelocateddownstreamofMOLbasketstrainersinMOLpumps common discharge line. A selector switch is provided to select the PCV depending upon which MOL basket strainer is on-line. Forminimumflow,fluidfromthedischargeof eachoftheMOLpumpsiscombinedand recycledbacktotheMOLpumpinletlineonpressurecontrol.AMOLrecyclecooleris provided on common minimum flow line to cool the recycled oil to 65 deg C before joining suction of the pumps. DOCUMENT TITLE: PROCESS AND UTILITY DESCRIPTION - CENTRAL DEGASSING STATION PROJ ECT No. :P 14364 ADCO DOC. NO.: 58.01.91.1601

REV 1DATE: 28-Sep-11 CONTRACTOR DOC. No. A049-001-02-41-PD-1001PAGE:9OF20 Corrosion inhibitor is injected in common suction line of MOL pump and biocide is injected in common dischargeline of MOL pump The MOL pumps are provided with MOV on suction and discharge line The MOV shall be linked to the start/stop logic of the MOL pump. When the pump starts, the MOV shall open. When the pump stops, the MOV shall close. MOL Pig Launcher, Receiver and ASAB Connections The crude oil is pumped about 80 km from the Qusahwira CDS facility to the ASAB CDS 2nd Stage Inlet Manifold. The pipeline system includes a MOL Launcher (58-01-LP-1303) at Qusahwira, a Pig Receiver at ASAB (14-01-RP-1311) and a MOL back pressure control station at the ASAB 2nd Stage Inlet Manifold. Backpressure on the MOL is controlled at the 2nd Stage Feed Backpressure Control Station downstream of the Pig Receiver. AnMOLPigLauncherisprovidedatCDSontheexportpipelinetoAsabtoallowfor periodic pigging operations, while a pig receiver is provided at ASAB. 4.5Produced Water Handling A produced water treatment and disposal system is required to handle the produced water at the CDS. Water produced with the reservoir fluids is separated from the crude oil in the Production Separators.The water effluent is drawn from the Production Separators on interface level control by a level control valve and combined into a common header which is then routed tothe Water Separation Tanks. In Phase-1 there are two Water Separation Tanks (58-01-T-2401/T-2402). Space is provided for three more tanks which shall be added in phase-2.Scaleinhibitor,deoiler,andbiocideareinjectedupstreamofWaterSeparationTankin commonline.Thereisalsoaprovisionofintermittentdosingofbiocideinupstreamof individual water separation tank.The water separation tanks are blanketed with fuel gas and maintained at pressure of 0.02 barg and vented to vapor recovery header. Hydrocarbon vapor may also degas from the water. The Water Separation Tanks are also equipped with internal oil skimmers to recover oilandreturnittotheProductionSeparatorsforreprocessingviatheRecoveredOil Collection Tank (58-01-V-1510). The Oil, forms a layer on the water, overflows a weir into the oil compartment. Oil level in the separator oil compartment is controlled by gap acting levelcontroller,withhighandlowalarms,whichopensthelevelcontrolvalveintheoil outlet line on high level and closes on low level. The Recovered Oil Collection Tank (58-01-V-1510) is underground and is blanketed with fuel gas, which is returned to the process through the Vapor Recovery Compressor. The RecoveredOilCollectionTankoperatingpressureis0.018barg.TheRecoveredOil CollectionTank(58-01-V-1510)ispumpedoutbythesubmersibletank-mounted Recovered Oil Return Pumps that operate in lead / lag mode.One pump pumps starts on high level with the second coming on-line should level continue to rise in the drum.The contents of the drum are pumped to the inlet of the production separators Oil content of the disposal water is limited to 1000 ppm. In phase-1 water from the Water Separation Tanks flows by gravity through a common line to the two Disposal Water Tanks (58-01-T-2404/T-2405) which provide surge volume for the system. Space is provided for an additional Disposal Water Tank which shall be added in phase-2. The Disposal Water Tanks are blanketed with fuel gas and maintained at pressure of 0.02 barg and vented to vapor recovery header. DOCUMENT TITLE: PROCESS AND UTILITY DESCRIPTION - CENTRAL DEGASSING STATION PROJ ECT No. :P 14364 ADCO DOC. NO.: 58.01.91.1601

REV 1DATE: 28-Sep-11 CONTRACTOR DOC. No. A049-001-02-41-PD-1001PAGE:10OF20 Water from Disposal Water tanks (58-01-T-2404/T-2405)is then pumped through Disposal Water pumps (58-01-P-2402-01/02/03/04/05) by a common line to the five Water Disposal WellsInphase-1therearefouroperatingandonespareDisposalWaterPumpand additional five pumps shall be added in Phase-2.The pumps combined flow is controlled by level control on disposal water tanks. An auto recycle valve is provided on discharge of each pump which is tied together with a common recycle header returning minimum flow recycles to the disposal water tank. Scale inhibitor is also injected in common suction line of Disposal Water Pumps. In phase-1 there are five produced water disposal wells. Flow towells from the disposal well header is balanced by manually adjusting a valve located near the well head 4.6Gas Compression and Distribution All gas produced at the Qusahwira facility shall be re-injected to maintain pressure on the Zone A/B field during Phase-1.The final pressure at the injection gas wells is 220.6 barg (3200 psig). The Produced gas from Production Separators flows on back pressure control to a common header to a spared reciprocating compressor train 4.6.1Gas Compressor: During Phase-1, the produced gas from Production separator is compressed in four stage spared reciprocating compressor. Induced draft air coolers are used for interstage cooling.The temperature control scheme first includes a variable speed control of cooler fan motors followedbylouverscontrolandfinallyoutlettemperatureiscontrolledbycoolerby-pass flow control.Each stage has a suction scrubber.The outlet of stage 2 has a discharge scrubberalso.Thesuctionpressureofeachstageiscontrolledbyaspillbacklinefrom dischargeofthecorrespondingstageofthecompressor.Thetwolowpressurestages compresswetgas.Thegasisdehydratedbetweenstages2and3bycountercurrent contactwithtri-ethyleneglycolinatrayedcontactor.DuringPhase-1,two100% reciprocatingcompressiontrainswilloperatewithdedicatedglycolcontactorssharinga common regeneration unit. Ist Stage Compression Produced gas from Separator and recovered vapors from Vapor Recovery Unit and Glycol FlashDrumaresenttoIststagesuctiondrum(Train-1:58-01-V-3111,Train-2:58-01-V-3121). The knocked out liquid is sent to Process Drain Drum (58-01-V-6702). Level of the suction drumis controlled by gap action level controller, with high and low alarms, which opens the level control valve on the liquid drain line on high level and closes on low level. GasfromIststagesuctiondrumflowsthroughtheoneoperatingandonestandbyIst StageSuctionStrainers(Train-1:58-01-ST-3111-01/02,Train-2:58-01-ST-3121-01/02),to 1stStageGasCompressor(Train-1:58-01-K-3111,Train-2:58-01-K-3121).Thesuction pressure is controlled by a control valve on spillback line from discharge of second stage suctiondrum.Thegasiscompressedfrom1.5bargto8.8bargandthancoolsin1st StageCooler(Train-1:58-01-E-3111,Train-2:58-01-E-3121).Theoutlettemperatureof cooler is 65 deg C in summer and 60 deg C in winter. 2nd Stage Compression Produced gas from 1st Stage Cooler (Train-1: 58-01-E-3111, Train-2: 58-01-E-3121) along with knocked out liquid from 2nd stage discharge drum and 3rd stage suction drum enters 2ndstagesuctiondrum(Train-1:58-01-V-3112-01,Train-2:58-01-V-3122-01).The knocked out liquid is sent to Production separator. Level of the suction drumis controlled by gap action level controller, with high and low alarms, which opens the level control valve on the liquid drain line on high level and closes on low level. DOCUMENT TITLE: PROCESS AND UTILITY DESCRIPTION - CENTRAL DEGASSING STATION PROJ ECT No. :P 14364 ADCO DOC. NO.: 58.01.91.1601

REV 1DATE: 28-Sep-11 CONTRACTOR DOC. No. A049-001-02-41-PD-1001PAGE:11OF20 Gas from 2nd stage suction drum flows through one operating and one standby 2nd Stage SuctionStrainers(Train-1:58-01-ST-3112-01/02,Train-2:58-01-ST-3122-01/02),to2nd StageGasCompressor(Train-1:58-01-K-3112,Train-2:58-01-K-3122).Thesuction pressureiscontrolledbyacontrolvalveonspillbacklinefromdischargeof2ndstage discharge drum.The gas is compressed from 8.1 barg to 35.9 barg and than cools in 2nd StageCooler(Train-1:58-01-E-3112,Train-2:58-01-E-3122).Theoutlettemperatureof cooler is 65 deg C in summer and 60 deg C in winter. The gas then enters a 2nd stage dischargedrum(Train-1:58-01-V-3112-02,Train-2:58-01-V-3122-02).Theknockedout liquid is sent to 2nd stage suction drum inlet. Level of the 2nd stage discharge drum is also controlled by gap action level controller, with high and low alarms, which opens the level control valve on the liquid drain line on high level and closes on low level The gas is dehydrated between stages 2 and 3 by counter current contact with tri-ethylene glycol in a trayed contactor which is described under Gas dehydration section 3rd Stage Compression Gas from the Glycol Contactor (Train-1: 58-01-C-311-01, Train-2: 58-01-E-3111-02) enters 3rd stage suction drum (Train-1: 58-01-V-3113, Train-2: 58-01-V-3123). The knocked out liquid is sent to 2nd stage suction drum inlet. Level of the suction drumis controlled by gap action level controller, with high and low alarms, which opens the level control valve on the liquid drain line on high level and closes on low level. Gas from 3rd stage suction drum flows through theone operating and one standby 3rd StageSuctionStrainers(Train-1:58-01-ST-3113-01/02,Train-2:58-01-ST-3123-01/02),to 3rdStageGasCompressor(Train-1:58-01-K-3113,Train-2:58-01-K-3123).Thesuction pressureiscontrolledbyacontrolvalveonspillbacklinefromdischargeof3rdStage Cooler.Thegasiscompressedfrom33.2bargto89bargandthancoolsin3rdStage Cooler (Train-1: 58-01-E-3113, Train-2: 58-01-E-3123). The outlet temperature of cooler is 65 deg C in summer and 60 deg C in winter. 4th Stage Compression Produced gas from 3rd Stage Cooler (Train-1: 58-01-E-3113, Train-2: 58-01-E-3123 enters 4thstagesuctiondrum(Train-1:58-01-V-3114,Train-2:58-01-V-3124).Theknockedout liquid is sent to 3rd stage suction drum inlet.Level of the suction drumis controlled by gap action level controller, with high and low alarms, which opens the level control valve on the liquid drain line on high level and closes on low level. Gasfrom4thstagesuctiondrumflowsthroughtheoneoperatingandonestandby4th StageSuctionStrainers(Train-1:58-01-ST-3114-01/02,Train-2:58-01-ST-3124-01/02),to 4thStageGasCompressor(Train-1:58-01-K-3114,Train-2:58-01-K-3124).Thesuction pressureiscontrolledbyacontrolvalveonspillbacklinefromdischargeof4thStage Cooler.The gas is compressed from 88.3 barg to 249.6 barg and than cools in 4thStage Cooler (Train-1: 58-01-E-3113, Train-2: 58-01-E-3123). The outlet temperature of cooler is 65 deg C in summer and 60 deg C in winter.For Phase-2, a third train using a centrifugal compressor will be added to handle all of the producedgas,whichwillbecompressed,dehydratedandthencompressedtoinjection pressure, as in Phase-1.Compressor trains 1 and 2 will then serve as partial spare units.Train 3 will have a dedicated glycol contactor and regenerator package. There will notbe enough produced gas to meet gas injection requirements. Therefore, gas will be imported fromGASCOAsabtomakeupthedifference.ThisgaswillbeaddedtoTrain3 downstream of the Glycol Contactor but upstream of the stage 3 suction scrubber.Lean gas may be added to Train- 1 & 2 in case Train-3 is down. Compressor vendors response is provided as an Annexure-1. The gas from Asab will have a maximum concentration of DOCUMENT TITLE: PROCESS AND UTILITY DESCRIPTION - CENTRAL DEGASSING STATION PROJ ECT No. :P 14364 ADCO DOC. NO.: 58.01.91.1601

REV 1DATE: 28-Sep-11 CONTRACTOR DOC. No. A049-001-02-41-PD-1001PAGE:12OF20 250ppmH2S.Itisnotintendedthatareciprocatingcompressorwilloperatewiththe centrifugal compressor in Phase-2. 4.6.2Injection Gas distribution The compressed gas is distributed to the CDS gas distribution system and RDS-1. The gas is transferred to RDS-1 by a 6 gas injection pipeline. An Injection Gas Pig Launcher (58-01-LP-3902)isprovidedatCDSontheexportpipelinetoRDS-1toallowforperiodic pigging operations. In CDS Gas from the Injection Gas Header is distributed by 3 branch lines to individual injection wells. During phase-1, there will be 4 gas injection wells in CDS. 4.7Gas Dehydration BetweenStages2and3ofeachcompressiontrain,theproducedgasisdehydratedby counter current contact with lean tri-ethylene glycol (TEG) in a 12-Trayed Glycol Contactor (Train-1: 58-01-C-3111-01, Train-2: 58-01-C-3111-02) drying the gas to 3 lbs H2O/MMSCF gas.DuringPhase-1,two100%reciprocatingcompressiontrainswilloperatewith dedicated glycol contactors sharing a common regeneration unit.The gas enters the bottom of the Glycol Contactor and contacts the TEG across 12 trays. Cooled lean TEG enters the top of the contactor. A dew point analyser is provided at outlet of the contactor. Normally gas flows from the contactor directly to the3rd Stage Suction Drum.On increasing pressure in the contactor gas is vented to the HP Flare on pressure control.RichTEGisdrawnoffonlevelcontrolfromthetrap-outtraybelowthebottom-most contacting tray of Glycol Contactor.The rich TEG then flows to the Reflux Condenser Coil (58-01-E-3116-01)oftheregenerationsystem(58-01-U-3116-01),whereitactsasthe cooling medium above the Still Column (58-01-C-3116-01).The preheated rich TEG then enters the Glycol Flash Drum (58-01-V-3116-01).Vapor from the flash drum flows back to the inlet of the LP compression trains. After the flash drum, the TEG is filtered through the spared Cartridge TEG Filters (58-01-S-3116-01/02)andtheCharcoalTEGFilter(58-01-S-3116-03).TherichTEGisfurther preheated in the TEG Lean / Rich Exchangers (58-01-E-3116-02/03/08) where it recovers heatfromtheleanTEG.Additionallean/richheatexchangeoccursintheCoilSurge Drum Cooler (58-01-E-3116-04). The rich TEG then enters the packed Still Column (58-01-C-3116-01) where hot gas strips waterandhydrocarbonsfromtheTEG.TheoverheadgaspassesthroughtheReflux CondenserCooler(58-01-E-3116-01)andthenflowstotheVaporRecoveryUnit.The partially stripped TEG enters the TEG Reboiler (58-01-V-3116-02) below the Still Column where the TEG Thyristor (58-01-E-3116-05) provides the heat input.The TEG is further strippedinthepackedStrippingColumn(58-01-C-3116-02)belowthereboilerbefore entering the Coil Surge Drum Cooler (58-01-E-3116-04).The lean TEG is cooled in the TEGLean/RichExchangers(58-01-E-3116-02/03/08).LeanTEGispumpedbyTEG Circulation Pumps (58-01-P-3116-01/02/03) and air cooled in Lean TEG Coolers (58-01-E-3116-06/07),andreturnedtothetopoftheGlycolContactor(Train-1:58-01-C-3111-01, Train-2: 58-01-C-3111-02). TheglycolregenerationareahasadedicatedGlycolDrainDrum(58-01-V-3101)and submersibleGlycolDrainPumps(58-01-P-3101-01/02),sothatanyTEGdrainedfrom equipment and piping can be handled separately form the Process and Closed Drains and recovered.TheGlycolDrainDrum(58-01-V-3101)isundergroundandisblanketedwith fuel gas, which is returned to the process through the Vapor Recovery Compressor. The DOCUMENT TITLE: PROCESS AND UTILITY DESCRIPTION - CENTRAL DEGASSING STATION PROJ ECT No. :P 14364 ADCO DOC. NO.: 58.01.91.1601

REV 1DATE: 28-Sep-11 CONTRACTOR DOC. No. A049-001-02-41-PD-1001PAGE:13OF20 GlycolDrainDrumoperatingpressureis0.2barg.TheGlycoldrainpumpsoperatein lead/lag mode.The contents of the drum are pumped to Glycol Flash drum through a Glycol drain filter 58-01-S-3101. 4.8Chemical Injection Systems Chemical Injection Packages will be provided at the CDS for Demulsifier (58-01-U-6201), Corrosion Inhibitor (58-01-U-6202), Biocide (58-01-U-6203), Water Deoiler (58-01U-6205) and Scale Inhibitor (58-01-U-6206).DemulsifierisinjectedupstreamofeachoftheProductionSeparatorwithaspared metering pump. TheCorrosionInhibitorPackageconsistsofHPheaderwhichispressurizedwithan operatingandaspareHPcorrosioninhibitorinjectionpump.ThisHPheadersupplies corrosion inhibitor to production headers leaving each MSM and test header. Additionally, a LP metering pumps with a spare supplies corrosion inhibitor to the production manifolds, upstream of each Production Separator and at upstream of the MOL Pumps.A common testchemicalstoragevesselisprovidedwhichishardpipedtothedemulsifierand corrosion inhibitor pumps for the testing of new chemicals. Biocide-1 is continuously injected upstream of the Water Separation Tanks with one set of meteringpumps.Anothermeteringpumpisprovidedtoalternatelyinjectbiocide-1& biocide-2 at the upstream of each Water Separation Tank to provide an intermittent dosing of biocide to one tank at a time.A second set of metering pumps (one operating and one spare) alternately inject biocide-1 & biocide-2 into the MOL line just upstream of the MOL Pig Launcher LP-1303. Water deoiler and Scale inhibitor are injected upstream of the Water Separation Tanks with metering pumps. Scale inhibitor is also injected in common suction line of Disposal Water Pumps. Each package has a spare for the metering pumps. The chemical storage vessels are filled from drums using portable pneumatic drum pumps. The chemical storage vessels have a 7 day capacity at maximum injection rates. Biocide dosing vessels are provided with 7 day capacity for continuous dosing and 24 hour capacity for intermittent dosing. A low level alarm is provided giving 24-hour notice to refill.The injectionmeteringpumpsaregravityfedfromthestoragevessels.Apotablewater connection is provided at injection pump suctions for system flushing and calibration. For design chemical dosing rates are based on chemical concentration in liquid phase of 10ppmw for corrosion inhibitor, 20 ppmw for demulsifier, 8 ppmw for scale inhibitor, 20 ppmw for continuous biocide, 500 ppmw for intermittent biocide and 20 ppmw for deoiler. For each chemical injection package, dedicated chemical drain pit/vessel is provided. For scaleinhibitor,biocide&deoilerlinedRCCpitsareprovidedforthepurpose.Whereas being flammable in nature corrosion inhibitor & demulsifier packages are provided with CS vessels.Drainsfromchemicalsystemsuchaschemicalstoragetankdrain,chemical storagetankoverflow,chemicalskidbaseplatedrainsetcareconnectedtoachemical drain pit/vessel. Chemical drain pit/vessel are installed below grade in order to allow gravity draining.4.9Vapor Recovery The Vapor Recovery System collects low pressure gases used to purge and blanket low pressuretanksanddraindrumsaswellastheoffgasfromtheglycolregeneration packages.Thesystemdischargestherecoveredgasintothesuctionlineofthe compression trains. One Vapor Recovery System is sized to handle the gas from both the phase-1 and phase-2.Tie-ins for a second Vapor Recovery System are provided should additional capacity be required in the future. DOCUMENT TITLE: PROCESS AND UTILITY DESCRIPTION - CENTRAL DEGASSING STATION PROJ ECT No. :P 14364 ADCO DOC. NO.: 58.01.91.1601

REV 1DATE: 28-Sep-11 CONTRACTOR DOC. No. A049-001-02-41-PD-1001PAGE:14OF20 TheVaporRecoveryCompressorisaLiquidRingtyperequiringa3phaseseparator, water recycle cooler and a water make up tank.The VRC Discharge 3-Phase Separator separates oil, gas, and water.The oil flows to the Process Drain.The gas flows to the common header feeding LP Compression Trains.The water is cooled in the VRC cooler and returned to the compressor. Intheeventthatthecompressorshutsdownorisnotoperating,fastactingblowdown valve divert the inlet gas to the Tank Flare System for disposal.A pressure control valve also diverts gas to the Tank Flare System if the suction pressure of the Compressor gets too high.Dedicated recycle lines are used to maintain positive pressure in the suction line. The Vapor Recovery Package (58-01-U-3801) is comprised of the following equipment: Vapor Recovery Compressor (58-01-K-3801). Mechanical Seal Pot (58-01-V-3802). VRC Cooler (58-01-E-3801). VRC Discharge 3-Phase Separator (58-01-V-3801). 4.10Fuel Gas FuelGasisprovidedthroughouttheplantfromtheFuelGasDistributionSystem.The systemtakesgasfromtheGlycolContactordischargelineandsendsthesametoFuel Gas Scrubber before distributing it to the plant. The Fuel Gas Scrubber (58-01-V-3201) is maintainedat3.0-3.5bargbyapressurecontrolonfuelgassupplyline.Whenthe compressedgasfromGlycolContactorisunavailable,thegaswillbetakenfromthe Production Separators overhead. Provision is made to supply lean gas from GASCO to the inlet of the fuel gas scrubber in Phase-2.Fuel gas distribution header supplying fuel gas for blanketing is provided with an automatic nitrogen backup actuated in case of low fuel gas pressure. Propane cylinders are also provisioned to be used during startup and as automatic back up forflarepilotsonlywhenfuelgassystemisnotavailable.Thepropanewillbeusedfor limited period for operator to take necessary action. 4.11Flare Systems 4.11.1HP, HP Cold and HP Spare Systems TheHP,HPColdandHPSpareFlareSystemsareinstalledtoventgasesthatarenot containedbytheprocessorrecycledthroughthevaporrecoverycompressor.TheHP Spare Flare is a common spare for both the HP and the HP Cold Flares.The flare systems include the following equipment: HP Flare Stack (58-39-FL-1921). HP Flare Knock-Out Drum (58-39-V-1921). HP Flare Knock-Out Drum Pumps (58-39-P-1921-01/02). The HP cold flare system includes the following equipments: HP Cold Flare Stack (58-39-FL-1911). HP Cold Flare Knock-Out Drum (58-39-V-1911). HP Cold Flare Knock-Out Drum Pumps (58-39-P-1911-01/02). The HP spare flare system includes the following equipments: HP Spare Flare Stack (58-39-FL-1931). DOCUMENT TITLE: PROCESS AND UTILITY DESCRIPTION - CENTRAL DEGASSING STATION PROJ ECT No. :P 14364 ADCO DOC. NO.: 58.01.91.1601

REV 1DATE: 28-Sep-11 CONTRACTOR DOC. No. A049-001-02-41-PD-1001PAGE:15OF20 HP Spare Flare Knock-Out Drum (58-39-V-1931). HP Spare Flare Knock-Out Drum Pumps (58-39-P-1931-01/02). The Flare Drain system includes the following equipments: Flare Drain Drum (58-39-V-6701). Flare Drain Pumps (58-39-P-6701-01/02). Lower pressure and wet areas discharge into the HP Flare Header and high pressure dry areasdischargetotheHPColdFlareHeader.TheHPSpareFlarecanbeattachedto eitherheaderthroughinterlockedvalvessuchthateachheadermustdischargeintoan appropriate flare system, and that the one flare system not in use must be closed off from the process. The flare systems are for emergency relief and shutdowns and have continuously lit pilots and flame detectors. The design flare flow rate for the HP flare is a case when full diversion of the produced gasfromproductionseparatorwithasimultaneousblowdownoftheTrain-3LP compression area and Glycol Contactor occurs. ThecontrollingcasefortheHPColdFlareheaderoccursduringasimultaneousblow downofthethirdandfourthstagesofthereciprocatingcompressortrain-1(or reciprocatingcompressortrain-2)andblowdownofthethirdandfourthstagesofthe centrifugal compressor train-3. FlareKnock-OutDrumsareabovegroundandareprovidedwithtwocentrifugalpumps operating in lead / lag mode.One pump starts on high level, followed by the second if the level continues to rise in the drum.Liquids accumulated in the Flare KO Drum are pumped into the inlet manifold. The Flare KO Drum Pump drains and instrumentation drain lines are locally drained to the Flare Drain Drum.The contents of Flare Drain Drum are pumped to the Closed Drain Drum. The flare header is purged continuously with nitrogen with fuel gas backup while in service.Flarepilotfuelgasissuppliedfromthefuelgassystemwithpropaneasback-up.A knockout standpipe is provided for the fuel gas upstream of the fuel gas pressure regulator and the flame front generator.The liquid will drain through a trap drain valve back to the respective flare knockout drum. 4.11.2Tank Flare System TankFlareSystemisinstalledtoventlowpressuregasesintheeventthattheVapor RecoveryCompressorisunavailableorisunabletomaintainasufficientlylowsuction pressure.Thesystemhasafullinstalledspare.Theflaresystemincludesthefollowing equipment: Tank Flare Stack (58-01-FL-1941). Tank Flare Knock-Out Drum (58-01-V-1941). Tank Flare Knock-Out Drum Pumps (58-01-P-1941-01/02). Spare Tank Flare Stack (58-01-FL-1951). Spare Tank Flare Knock-Out Drum (58-01-V-1951). Spare Tank Flare Knock-Out Drum Pumps (58-01-P-1951-01/02). DOCUMENT TITLE: PROCESS AND UTILITY DESCRIPTION - CENTRAL DEGASSING STATION PROJ ECT No. :P 14364 ADCO DOC. NO.: 58.01.91.1601

REV 1DATE: 28-Sep-11 CONTRACTOR DOC. No. A049-001-02-41-PD-1001PAGE:16OF20 The Tank Flare System is designed as a back up to the Vapor Recovery System and is sized to handle the full capacity of the Vapor Recovery System should it not be available.The Tank Flare System is for emergency relief and shutdowns and has a continuously lit pilot and flame detector. FlareKnock-OutDrumsareabovegroundandareprovidedwithtwocentrifugalpumps operating in lead / lag mode. One pump pumps down on high level with the second coming on-lineshouldlevelcontinuetoriseinthedrum.LiquidsaccumulatedintheFlareKO Drum are pumped into the Production manifold.Flare KO Drum Pump drains are locally drained to the Flare Drain Drum.The flare header is purged continuously with nitrogen with fuel gas backup while in service.Flarepilotfuelgasissuppliedfromthefuelgassystemwithpropaneasback-up.A knockout standpipe is provided for the fuel gas upstream of the fuel gas pressure regulator and the flame front generator.The liquid will drain through a trap drain valve back to the respective flare knockout drum.Below in Table 3-1 are the HSE Requirements for allowable flare radiation and dispersion. 4.11.3Flare Drain System A flare drain system is provided to drain vessels and piping in flare area for maintenance operations.The flare drain system includes the following equipment: Flare Drain Drum (58-39-V-6701). Flare Drain Pumps (58-39-P-6701-01/02). Theflaredrainheadersystemisundergroundandpurgedwithnitrogen,withfuelgas backup.The flare Drain Drum is floating on tank flare.The flare Drain Drum is installed below grade and is pumped out by the submersible tank-mounted flare Drain Pumps that operate in lead / lag mode.One pump pumps starts on high level with the second coming on-line should level continue to rise in the drum.The contents of the drum are normally pumped to the closed drain header. 4.12Process and Closed Drains 4.12.1Closed Drain System A closed drain system is provided to drain vessels and piping for maintenance operations.The closed drain system includes the following equipment: Closed Drain Drum (58-01-V-6701). Closed Drain Drum Pumps (58-01-P-6701-01/02). Thecloseddrainheadersystemisundergroundandpurgedwithfuelgas.TheClosed Drain Drum is blanketed with fuel gas, which is returned to the process through the Vapor Recovery Compressor. The Closed Drain Drum operating pressure is 0.2 barg. TheClosedDrainDrumispumpedoutbythesubmersibletank-mountedClosedDrain Pumpsthatoperateinlead/lagmode.Onepumppumpsstartsonhighlevelwiththe second coming on-line should level continue to rise in the drum.The contents of the drum arenormallypumpedtotheinletoftheproductionseparators.IftheWaterSeparation Tanks or Water Disposal Tanks have been drained to the drum, then the contents may be pumped to the Water Separation Tanks instead. Closed Drain Drum is installed below grade in order to allow gravity draining from the flow lines into the drum. DOCUMENT TITLE: PROCESS AND UTILITY DESCRIPTION - CENTRAL DEGASSING STATION PROJ ECT No. :P 14364 ADCO DOC. NO.: 58.01.91.1601

REV 1DATE: 28-Sep-11 CONTRACTOR DOC. No. A049-001-02-41-PD-1001PAGE:17OF20 4.12.2Process Drain System The Process Drain System is installed to accept online waste streams from the process for recyclingbacktotheproductionseparators.Theprocessdrainsystemincludesthe following equipment: Process Drain Drum (58-01V-6702). Process Drain Drum Pumps (58-01-P-6702-01/02). Process drains are routed to the Process Drain header that feeds the Process Drain Drum. A dedicated drain header is provided for each piping class.The system is operated under afuelgasblanket,andventedtothevaporrecoveryheader.TheProcessDrainDrum operating pressure is 0.2 barg. The Process Drain Drum is pumped out by the submersible tank-mounted Process Drain Pumps that operate in lead / lag mode.One pump starts on high level, with the second comingon-lineshouldlevelcontinuetoriseinthedrum.Thecontentsofthedrumare pumped to the production separators. The Process Drain Drum is installed below grade in order to allow gravity draining from the flow lines into the drum. 4.12.3Tundish SystemA Tundish System is provided to collect hydrocarbons from drip pans at the pig launchers andreceivers,compressorsandpumpsandthedieselsupplysystem.Collected hydrocarbon drains by gravity to a below ground atmospheric tank i.e. Tundish Drain Sump (58-01-V-6703)andthenpumpedtotheClosedDrainHeaderbysubmersibletank mounted Tundish Drain Pump (58-01-P-6703). One warehouse spare pump without motor is also provided. 4.13Compressed Air System A Compressed Air System is provided for instrument air, plant air, and nitrogen generation. The Air Compressors and Dryer Package, includes the following equipment items: Air Compressors (58-01-K-6101/K-6102/K-6103/K-6104).TheAirCompressorconfigurationis2leadcompressor,onelagcompressorandone standby. Instrument Air Dryer System (58-01-D-6101-01/02).The Instrument air dryer configuration is two duplex desiccant dryers, each dryer shall be have two columns, one operating and other under regeneration. These are heatless type dryers with automatic regeneration by purge air. Additionally, the air compression system includes the following equipment items: Instrument Air Receiver (58-01-V-6111). Plant Air Receiver (58-01-V-6110). In addition to supplying the CDS instrument air requirements the Compressed Air System supplies instrument air to the CDS Nitrogen Generation System as feed, the Flare Flame Front Generators and the utility stations.The instrument air dryer is a two column system, oneofwhichisindryingmodewhiletheotherisinregeneration.Asecondairdryer package is provided as a spare.Instrument air is supplied at 9.5 barg max, depending on thepressuredropthroughthedryer,butnotlessthan4.2bargatInstrumentairdryer outlet.The Air Compressors will operate with two operating as lead, one operating as lag, and one as a spare, each with a rated capacity of 1500 Nm3/h.The priority of compressed DOCUMENT TITLE: PROCESS AND UTILITY DESCRIPTION - CENTRAL DEGASSING STATION PROJ ECT No. :P 14364 ADCO DOC. NO.: 58.01.91.1601

REV 1DATE: 28-Sep-11 CONTRACTOR DOC. No. A049-001-02-41-PD-1001PAGE:18OF20 airsupplyisfirsttotheinstrumentairheadersfollowedbynitrogengenerationwiththe plant air system being the lowest priority. 4.14Nitrogen Generation System ANitrogenGenerationSystemwithtwotrainsisprovidedfortheCDS.TheNitrogen Generation Packages, U-6911/21, includes the following equipment items: Coalescing Filters (58-01-S-6911-01/02/03/04/05/06/S-6921-01/02/03/04/05/06). Membrane Separators (58-01-S-6912/-01/02/03/04/S-6922-01/02/03/04). Electric Heater (58-01-H-6911-01/ H-6921-01). Additionally, the Nitrogen Generation System includes the following equipment items: Nitrogen Receiver (V-6901). TheNitrogenGenerationPackageissuppliedwithairatabout9.0barg(max)fromthe Compressed Air System.Nitrogen is supplied at 8.0 (max) barg (at nitrogen package B/L), butnotlessthan4.2barg,withapurityof98%minimum.NitrogenfromtheNitrogen Receiver provides purge and seal gas to the compressors, HP Flare Header, HP Cold Flare Header, Tank Flare Header, and Utility Stations inside the CDS.The Nitrogen Generation Packages each have a rated capacity of 595 Nm3/hr. 4.15Diesel Fuel TheDieselFuelSystemisprovidedfortheCDStosupplydieselfueltotheEmergency GeneratorandFirewaterPumpP-5101.Thesystemcontainsthefollowingequipment items: Diesel Storage Tank (58-01-T-6301) One operating and one standby Diesel Transfer Pump (58-01-P-6301-01/02) Diesel Fine Filter (58-01-S-6301) A truck connection is provided on the Diesel Storage Tank to allow a tank truck supply of diesel fuel.The transfer pumps supply diesel to the Firewater Pump Fuel Day Tank and the Emergency Generator Day Tank via the Diesel Fine Filter. These pumps are provided withaminimumflowcirculationline.Thetransferpumptripsintheeventoflowlevelin tank. In addition there is a low and high level alarm in DCS indicating for tank refill or pump trip. 4.16Emergency Diesel Generator The emergency diesel generator is not working during normal operation. It shall start on low voltage in case the normal power supply fails. 4.17Potable Water System Potable water system consist of Potable Water Generation System Potable Water Storage and Distribution 4.17.1Potable Water Generation System APotableWaterGenerationSystemshallbeprovidedattheCDS.Feedwatertothe PotableWaterTreatmentPackageissuppliedfromdedicatedwatersupplywellswith submersiblepumps(suppliedbyADCO).Thepackageshallproduce1000m3/dayof potable water.The Package shall consist of Pre-Treatment section for treatment of Raw WaterreceivedfromtheROFeedWaterTanks,aTwo-StageFiltrationsystem,High Pressure RO feed Pumps and RO skids to produce potable water quality as per ADNOC Specifications for Drinking Water. The potable water shall fill the potable water tanks (58- DOCUMENT TITLE: PROCESS AND UTILITY DESCRIPTION - CENTRAL DEGASSING STATION PROJ ECT No. :P 14364 ADCO DOC. NO.: 58.01.91.1601

REV 1DATE: 28-Sep-11 CONTRACTOR DOC. No. A049-001-02-41-PD-1001PAGE:19OF20 01-T-2303/04)whicharesizedforacombinedworkscapacityof3days(1-1/2daysper tank)atCDS.AtankerconnectionisalsoprovidedoutsidetheCDSfenceforfillingthe storage tanks.Accommodations will be provided with additional potable water storage. The potable water pumps shall supply water to the CDS water supply system and the dedicated pumps are provided to the pipeline going to the accommodations area. TheRejectWaterfromthePotableWaterTreatmentpackageshallbesenttotheRO Reject Water Tank and then pumped into a disposal well with the RO Reject Water Pump. 4.17.2Potable Water Storage and Distribution Inlet Facility Inlet for potable water is provided from ADWEA by a dedicated line controlled by MOVs to potable water storage tanks. Apart from this provisions are also kept for filling the storage tanks from:- Tanker, for which a coupling connection is provided with a ball valve and a check valve. PotableWaterTreatmentPackage,forwhicha dedicatedlinefrompotablewater treatment package (refer section below) to potable water storage tanks is provided with MOVs. Storage Potable water is stored in two numbers potable water tanks (T-2303 & T-2304) having a capacityof1500m3each.Eachtankisprovidedwithappropriateappurtenancesfor maintenance of tank and proper functioning of the system.Pumping and Distribution Potablewaterpumpsconsistoffournumbersofpumps(2operatingand2standbys). These pumps draw suction from a common suction header, which receives water from both the tanks and pumps it directly to the distribution network.Twonumberpumps,oneworkingandonestandby(P-2303-01&P-2303-02)ofrated capacity25m3/hranddischargepressureof6.213bargareprovidedforpotablewater distribution to the following: Safety Shower/ Eye wash unit Control RoomSub Station Entry Building Utility Stations Potable water makeup drum Pig ReceiversTo MOL Launcher Injection Gas Station Apart from these, connections are also provided from these pumps for Controlling the pumps flow by level control on potable water storage tanks Makeup water line to fire water tanks with shut down valve. DOCUMENT TITLE: PROCESS AND UTILITY DESCRIPTION - CENTRAL DEGASSING STATION PROJ ECT No. :P 14364 ADCO DOC. NO.: 58.01.91.1601

REV 1DATE: 28-Sep-11 CONTRACTOR DOC. No. A049-001-02-41-PD-1001PAGE:20OF20 Auto recycling of minimum flow of pumps back to potable water tank by means of flow control valve Two number dedicated pumps, one working and one standby (P-2303-03 & P-2303-04) of rated capacity 70m3/hr and discharge pressure of 12.6 barg are provided for potable water supply to the following: Camp Accommodation WorkshopFire Station Administration Building Laboratory 5.0REFERENCES 1.Process Design Basis: Qusahwira, Project Document No. A049-000-02-41-DB-1001, ADCO Document No. 58-99-91-1625. 2. EquipmentSizingPhilosophy,EILDocumentNo.A049-000-02-41-DP-1004,ADCO Document No. 58-99-91-1605.3. Process Description Qusahwira Remote Degassing Stations, Project Document No A049-011-02-41-PD-1001., ADCO Document No. 58-11-91-1601.6.0ANNEXURES 1.Compressor vendor confirmation for operability of reciprocating compressor with lean gas. Annexure-1 Sheet 1 of 4Annexure-1 Sheet 2 of 4TM0208 NPCC/ADCOInjection Gas Compressor Study of Parallel Operation Lean gas (MW=18.37)Item No; 58-01-K-3111-3114 10MMSCFD (9155kg/H) and 58-01-K-3121-3124Case-1AREQUIRED CAPACITY 5MMSCFD 15MMSCFD 15MMSCFDMFGR.'S RATED CAPACITY MMSCFD 9.29MMSCFD 9.71MMSCFD 16.81MMSCFD 12.58MMSCFDkg/H 14067 15656 11037 20192 15112MOL.. WT. 30.4 32.34 24.1 24.1LOAD 50% 50% 100% 100%SUC. PRESSURE @PUL.SUPP. BARA 2.49 9.1 34.16 88.3SUC. TEMPERATURE 58.9 53.3 64.2 64.8DIS. PRESSURE @PUL.SUPP. BARA 9.8 36.9 90 250.6DIS. TEMPERATURE 134 129 132 144kW/STAGE 613 600 717 580TOTAL kW 2510Lean gas (MW=18.37)Case-1B 10MMSCFD (9155kg/H)REQUIRED CAPACITY 5MMSCFD 15MMSCFD 15MMSCFDMFGR.'S RATED CAPACITY MMSCFD 9.29MMSCFD 9.71MMSCFD7.19MMSCFD 16.87MMSCFD 13.76MMSCFDkg/H 14067 15656 22239 18137MOL.. WT. 30.4 32.34 26.45 26.45LOAD 50% 50% 100% 100%SUC. PRESSURE @PUL.SUPP. BARA 2.49 9.1 34.16 88.3SUC. TEMPERATURE 58.9 53.3 64.2 64.8DIS. PRESSURE @PUL.SUPP. BARA 9.8 36.9 90 250.6DIS. TEMPERATURE 134 129 129 139kW/STAGE 613 600 700 603TOTAL kW 2516MES's Confirmation (2011/5/27) Injection gas compressor will be able to operate at Lean gas case (Case 1 and Case-2) as above caluculation result.3rd stage 4th stageFrom SeparatorSaturated gas1st stage 2nd stageContactorGDV4th stageFrom SeparatorSaturated gas1st stage 2nd stageContactorGDV+ 6583Lean gas4619kg/H3rd stageLean gas+ 9155 10MMSCFDAnnexure -1Sheet 3 of 4TM0208 NPCC/ADCOInjection Gas Compressor Study of Parallel Operation Lean gas (MW=18.37)Case-2 6.5MMSCFD (5951kg/H)REQUIRED CAPACITY 8.5MMSCFD 15MMSCFD 15MMSCFDMFGR.'S RATED CAPACITY MMSCFD 18.81MMSCFD 19.98MMSCFD 16.89MMSCFD 14.16MMSCFDkg/H 28488 32190 16805 22756 19073MOL.. WT. 30.4 32.34 27.03 27.03LOAD 100% 100% 100% 100%SUC. PRESSURE @PUL.SUPP. BARA 2.49 9.1 34.16 88.3SUC. TEMPERATURE 58.9 53.3 64.2 64.8DIS. PRESSURE @PUL.SUPP. BARA 9.8 36.9 90 250.6DIS. TEMPERATURE 131 127 128 138kW/STAGE 1242 1236 696 611TOTAL kW 37853rd stage 4th stageFrom SeparatorSaturated gas1st stage 2nd stageContactorGDV15385kg/HLean gas+ 5951 6.5MMSCFDAnnexure - 1 Sheet 4 of 4